Hammer



Dc. 30, 1958 J. F. FREEMAN EI'AL' 2,866,199

HAMMER Filed Oct. 19, 1955 3 Sheets-Sheet l I 68 i s| 3 INVENTORS I JOHNFFREEMAN l I ALBERT M.ROCKWOOD 1 29 y JAMES w SMELKER W aw ATTORNEY Dec.30, 1958' FREEMAN ErAL HAMMER 3 Sheets-Sheet 2 "I'll" Filed Oct. 19,1955 INVENTORS. N F. FREEMAN ERT Mv ROCKWOOD JOH ALB BY JAMES W. SMELKERATTORNEY J. F. FREEMAN ETAL 2,866,199

Dec. 30, 1958 HAMMER 3 Sheets-Sheet 3 Filed Oct. 19, 1955 ODO IN VENTORS F. FREEMA N WOOD KER T M. ROCK W. SMEL JOHN ALBER BY JAMES ATTORNEYUnited States harem HAMMER John F. Freeman, Worthington, and James W.Smelker and Albert Miller Rockwood, Columbus, Ohio, assignors, by mesneassignments, to Bond Nail, Incorporated, Columbus, Ohio, a corporationof Ohio Application October 19, 1955, Serial No. 541,326

7 Claims. (Cl.-146) The inventions disclosed in this application relateto nailing machines and are particularly useful in connection withsemi-automatic nailing machines which are portable and which areoperated by striking a reciprocating plunger with a hammer or mallet. Itis illustrated by such a semi-automatic nailing machine.

Many such nailing machines have been heretofore designed. While savingmuch valuable skilled labor in that one man can by the use of suchmachines drive many more nails than he can by the old fashioned way ofdriving nails yet such nailing machines have either been heavy,cumbersome and hard to handle or are subject to frequent breakage thuscausing frequent work stoppages.

It is an object of our invention to provide a semi-automatic nailingmachine which is both light in weight and rugged in construction, thushaving ease of operation and substantial absence of failure.

A further object of our invention is to provide such a semi-automaticnailing machine which is easy to load and reload.

The semi-automatic nailing machines in which our inventions areespecially useful are as stated operated by striking a reciprocatingplunger with a hammer or mallet. In actual practice in the use of suchportable semi-automatic nailing machines, the blows from the hammer ormallet are often not perfectly aligned with the plunger. That is, theblows usually glance off the plunger at varying angles of deflection.This causes the plunger to tend to rotate about its longitudinal axis.If the plunger is not allowed to rotate, the force tending to rotate itwill cause the plunger to wear unevenly and may often cause something tobreak.

It is therefore a further object of our invention to provide a drivingmeans which uses a cylindrical plunger to actuate a floating naildriving blade whereby the plunger is at all times free to rotate,resulting in uniform wear of the plunger shaft and a minimum ofbreakage.

Also, in the type of nailing machine to which our invention especiallyrelates, the plunger reciprocates downward and upward, the downwardforce being supplied by the hammer striking the plunger and the returnor upward moving force being supplied by a spring which tends to drivethe plunger upward out of the housing. It is therefore necessary to stopthe upward movement of the plunger when the plunger reaches itsoutermost predetermined position, an operation which produces impactforces having magnitudes sufiicient to shear a stopping or retainingpin.

It is a further object of our invention to provide novel means forstopping the plunger when it reaches its predetermined outermostposition.

More specifically, it is a further object of our invention to providemeans for resiliently stopping the plunger when it reaches itspredetermined outermost position so that the impact forces are reducedto within non-shearing limits.

As stated above, many such nai ing machines have been heretoforedesigned. In genera these machines are constructed with a work surfaceengaging face whichis de- 'signed to make face to face contact with theboard or surface to be nailed when the machine is in proper nailingposition. The work surface engaging face of a given nailing machine isarranged so that it cooperates with the rest of the structure to fix theangle at which nails will be driven into the work surface. Since thework surface engaging face is not usually adjustable, a given nailingmachine can usually properly drive nails at only one angle, and is not asatisfactory instrument for driving nails at other angles. Although anailing machine adapted to. properly drive nails at one angle may beused to drive nails at other angles by tilting the machine so that thework surface engaging face makes an angle with the work surface, theresults are not likely to be satisfactory.

Therefore, where a workman has occasion to drive nails bothperpendicular tothe work surface, which is ice generally the case whenhe is putting down sub-fiooring,.

and at an angle of approximately 45 with the work' surface, which isgenerally the case when he is putting down finished flooring, he isrequired to use two different nailing machines. Moreover, the nails usedfor the sub-flooring are usually thicker and have a larger head than thenails used for securing the finished flooring. This requires the workmanto carry an additional nailing machine from job to job, which addsweight and takes up valuable space in his tool chest and presents, inaddition, an unnecessary economic burden.

It is therefore an object of our invention to provide a portable nailingmachine which is adaptable to driving nails at more than one angle withthe work surface. 7

It is a further object of our invention to provide a nailing machine inwhich the nail driving means is carried in a housing and nails arecarried in a nail carrying means including a nail magazine,disengageably secured to the housing from which the nails are fed intocooperating position with the nail driving means so that the nails canbe driven from the machine.

It is a further object of our invention to provide an arrangement inwhich the nail carrying means, including the nail magazine, has a worksurface engaging face, whereby the nail carrying means cooperates withthe housing to determine the angle at which the nails will be driveninto the work surface when the work surface engaging face is in face toface contact with the work surface.

It is a further object of our invention to provide an arrangementwhereby the nail carrying means, including the magazine, may be removedeasily and quickly from the housing.

It is a further object of our invention to provide a nailing machinehaving interchangeable nail carrying means each cooperating with thehousing to drive nails at a different angle and if desired to supplydifferent types of nails so that nail carrying means cooperating todrive one type of nail at one angle with the work surface may bereplaced easily and quickly by nail carrying means cooperating to drivethe same or a different type of nails at a different angle with the worksurface.

Further obiects and features of our invention will be understood fromthe following specification and claims when considered in connectionwith the accompanying drawings illustrating an embodiment of ourinvention.

In the drawings illustrating an embodiment of our invention:

Fig. 1 is a side elevational view, partly in section, of one embodimentof our invention;

Fig. 2 is a rear elevational view of said embodiment of our inventionwith the nail ston plate removed and with the means for positivelyurging nails through the nail carrying me ns removed, and also with theupper and lower parts of the machine broken away;

Fig. 3 is a sectional view taken along line 3-3 of Fig. 1 with the meansfor positively urging nails through the nail carrying means removed;

Fig. 4 is a sectional view taken along line 4-4 of Fig. 1;

Fig. 5 is a sectional view taken along line 5--5 of Fig. l;

Fig. 6 is a sectional view taken along line 6-6 of Fig. 4;

Fig. 7 is an enlarged view of the plunger retaining means shown in theembodiment of Fig. 1;

Fig. 8 is a front elevational view of the stripper plate; P Fig. 9 is aside elevational view of the stripper plate of Fig. 10 is a sideelevational view of the blade; and

Fig. 11 is a plan view of the drive washer.

Referring now to Fig. 1, it is seen that the embodiment of our inventionillustrated comprises generally a housing 20, a nail driving means 40received in the housing 20, and a nail carrying means 60 disengageablysecured to housing 26, a nail aligning means 72 secured to nail carryingmeans 60, and a nail feeding means 90 pivotally secured within housingfor feeding nails one at a time into cooperating position with the naildriving means 40 so that said driving means 40 may drive the nails andthus eject them from said nail aligning means 72.

Still referring to Fig. 1, it is seen that the housing 29 comprises ahollow generally horizontal U-shaped body 21 (also shown in Fig. 3)closed at both ends, and a generally vertical head 22 extending upwardlyfrom one end of the body 21. As particularly seen in Fig. 3, the body 21has an inwardly projecting longitudinal and horizontal ear or flange 23,partially closing its open lower side. The ear or flange 23 has amachined face 24, which face is perpendicular to the longitudinal axisof the head 22. The housing 20, preferably cast from aluminum alloy, iscast integral with a bored pre-cast steel sleeve 25, in which the naildriving means 40 reciprocally operates. The longitudinal axis of thesleeve 25 coincides with the longitudinal axis of the head 22 so thatthe bore of said sleeve is thus perpendicular to the machined face 24.Axially disposed along the periphery of the bore of the sleeve 25 is arectangular keyway 26 which is positioned so that it extends outwardfrom the bore toward the front of the housing 20. This keyway 26 isprovided as a guideway for the driving blade and for an ear on the drivewasher (all of which will be described fully later herein) and as a shoewhere by said blade and washer may be initially assembled and wherebythe parts may be afterwards disassembled should need arise. The keyway26 is in communication with the front face of the head 22 by means of aradial passage 27 spaced downward from the top of said head and havingits central axis perpendicular to the root face of said keyway. Thepassage 27 (Fig. 7) extends through the head 22 and through the sleeve25 and is countersunk in the sense that the bore 27a or portion of thepassage within the head 22 has a larger diameter than the diameter ofportion 27b of the bore 27, through the wall of the sleeve 25. Theportion 27a extends from the outer face of the front side of the head 22to the outer face of the sleeve wall and is provided with threads sothat the passage 27 may threadably receive retaining means 51 associatedwith the driving means which will be described in full at a later point.

Extending rearwardly from the body 21 is a generally verticallongitudinally extending ear 28 having a hole passing laterally throughit, said ear constituting part of means for aligning the rear end of thenail carrying means 60 with the rear end of the nail driving means 40pivotally connecting the nail carrying means 60 to the housing 20. Alsothe base 21 is enlarged at the front at the lower part of the head 22laterally outward from each side of its base as at 29 (see Fig. 2). Theenlargements on each side have a vertical hole into each of which ispressed a dowel pin, such as pin 30, to provide an appropriate standoutwhich constitutes means cooperating with the nail carrying means toalign the front end of said nail carrying means 60 with the front end ofthe nail driving means 40. The base of the head 22 also has afrontwardly extending projection 31 (see Fig. 1) for cooperating withthe nail carrying means 60 to disengagingly hold said nail carryingmeans in a closed position relative to the housing 20. The top of thebody 21 and back side of the head 22 are provided with threaded holes sothat a handle 32 may be attached thereto by screws such as 33.

Still referring to Fig. 1, it is seen that the nail carrying means 60comprises a magazine 61 having a machined horizontal face 62 whichengages the face 24 of housing 20 in face to face contact, and ispreferably cast from aluminum alloy. Extending vertically from themachined face 62 of magazine 61 and adjacent to one end thereof are twolongitudinally extending, laterally disposed ears 64 and 65 (seen bestin Fig. 2) each having a hole passing laterally through it, so that whenear 28 is positioned between ears 64 and 65, the lateral holes passingrespectively through each ear will align with one another and cooperatein receiving a hinge pin 66 to provide the pivotal means connecting thehousing 20 to the nail carrying means 60. The pin 66 is of conventionaltype and is removably maintained in position by snap rings such as 67.If necessary, shims may be disposed between the contact surfaces of theears to eliminate galling of the two contacting aluminum surfaces and toeliminate any excessive side play of ears 64 and 65 relative to ear 28.This structure completes the means for aligning the rear end of the nailcarrying means with rear end of the nail housing referred to above.

Passing longitudinally through the magazine there is a generallyinverted L-shaped nail guiding passage 68 (best seen in Figs. 2 and 3)having one leg vertical and the other leg horizontal and arranged toform an exposed longitudinal horizontal lip 6?, spaced from but adjacentto the machined face 62, upon which nails may be slidably moved throughthe nail guiding passage 68 and therefore longitudinally through themagazine 61. As is seen in Fig. 3, the ear 23 of body 21 provides apartial roof for the nail guiding passage 68 whereby the nails in saidpassage would be prevented from falling out the top if the nailingmachine were upset. Closing the entrance of the nail guiding passage 68,at the pivoted rear end of the ma azine 61, is a nail stop plate 70 (seeFig. l) removably secured to the back face of the magazine 61 by meansof a single bolt, such as 71. Secured to the vertical lateral front faceof magazine 61 farthest from the pivoted end is a nail aligning meanscomprising an assembly 72, which receives nails from the nail guidingpassage 68 and aligns them, one at a time, in cooperating position withthe nail driving means 40 so that one nail. will be ejected from thecarrying means 60 for each operation of the nail driving means 40.

Referring generally to Fig. 1, and also particularly to Figs. 4, 5, 6, 8and 9, it is seen that aligning means 72 comprises a generally channelshaped front plate 73, preferably made of steel, having forwardlyextending generally horizontal ribs 74 and 75. The front plate 73 has acentrally located rectangular vertically extending driving throat 76along the face opposite to that from which ribs 74 and 75 extend.Disposed between the plate 73 and the magazine 61 and making face toface contact therewith is a stripper plate 77, preferably made fromsteel, having an inverted L-shaped passage therein aligned with theinverted L-shaped nail guiding passage 68 and connecting said passagewith the driving throat 76. The front plate 73 and stripper plate 77 aresecured to the magazine 61 in their properly aligned positions by meansof suitable fasteners such as bolts 78. The face of the plate 77 incontact with the plate 73 has its upper lateral edge chamfered as at 77afor reasons which will be described amma later. The plate 73 has twovertical holes such" as, 79 which are positioned to receive the pins .30and cooperate with said pins to properly align the front end of the nailcarrying means 60 with the housing 20. Attached to the front of theplate 73 is a latch spring 80 which cooperates with the projection 31 ofthe housing 20 to disengagingly lockthe nail feeding means 60 to thehousing 20. p

v The nail driving means 40 will now be described. Referring generallyto Fig. 1, it is seen that the nail driving means 40 comprises acylindrical plunger 41, preferably made of steel, slidably and rotatablyreceived in the bore of the sleeve 25. The plunger 41 has an enlargedhead 42 formed at its upper end and has, adjacent to its lower end, twoannular grooves 43 and 44, spaced axially from each other. Received ingroove 43 is a horseshoe shaped drive washer 45, preferably made fromsteel, having an car 46 (best shown in Fig. 11) and arranged so that theplunger 41is free to rotate within the central opening of drive washer45 while the ear 46 slidably moves in the keyway 26. Also slidablyreceived in the keyway 26 and in cooperating position with the ear 46 ofthe drive washer 45 is a floating blade 47. The blade 47 has aprojection 48 which is received by groove 44 so that the blade isfloatingly carried by the plunger 41. That is, the blade 47 is free tomove relative to the plunger 41 for small distances longitudinally whileplunger 41 remains free to rotate within the bore of sleeve 25'. Whenthe plunger 41 is stationary or is moving upward, the blade 47 iscarried by the lower lip of the annular groove 44. When the plunger ismoved downward, such as by a blow from a hammer, the blade 47 floatsupward relative to the plunger 41 until its upper end comes in contactwith'the car 46 of the drive washer 45 at which point the downward forceof the plunger 41 is transmitted through the drive washer 45 to theblade 47 thereby driving the blade 47 downward- This type ofconstruction including the drive washer 45 allows the use of highstrength material to withstand impact and at the same time allows theuse of a less expensive plunger. The washer 45 thus allows the use of asolid plunger which is necessary to keep the plunger from breaking. Thistype of construction prevents uneven wear on the plunger wall, due toglancing blows of the hammer striking the head, normally asociated withnailingmachines havinga square or rectangular plunger. A

glancing blow tends to rotate the plunger, which would cause uneven wearon the wall of the plunger if the plunger were prevented from rotating.The arrangement just described overcomes this difficulty since theplunger is at all times free to rotate. The lower end of the blade 47 isslidably guided by the keyway 76 of the plate 73, which is in alignmentwith keyway 26, and is thus guided into cooperating position with thehead of the nail to be driven, where it engages said nail, driving itfrom the nail feeding means 60. The upper portion of the blade 47 isalways maintained in sliding contact in the keyway 26 by the plunger 41.When the plunger is in its uppermost position the lower end of the bladeis slidably received in driving throat 76, and is maintained in slidingcontact therewith by means of a retainer plug 49 which is pressed intothe bore of the sleeve 25 and has its bottom face complementing housing20 in completing the machined face 24. So that only one nail will bedriven at a time, the thickness of the blade 47 must be slightly smallerthan the thickness of the thinnest nail to be driven; and the keyway 76must be of a thickness slightly greater than the thickest nail to bedriven and slightly smaller than twice the depth of the thinnest nail tobe driven. The driving means 40 has a compression spring 50. The designof this spring is important. An external spring can thus be used havinga low spring rate and giving a uniform distribution of return forcewhich keeps the plunger from binding. The spring 50 surrounds the shaftof the plunger 41. It has one of its ends in contact engagement with thehead 42 of the plunger 41 and has its other end in contact engagementwith the top of sleeve 25 The 6 spring'50 operates at all timesto'urgethe plunger upward in sleeve 25, thereby providing the means forreturning the plunger 41 to its uppermost position after a nail has beendriven. I

To prevent the spring 50 from driving the plunger 41 clear out of. thesleeve 25, we provide'a'retaining means 51 which operates to stop theupward movement of the plunger41at a predetermined point. As shown indetail in Fig. 7, the retaining means51 includes an externally threadedplug 52.having an enlarged head 53 formedat one end. Passinglongitudinally through the plug 52 is a substantially cylindricalpassage 54. However, formed at the innerend of passage 54"is'a roundedinwardly projecting annular rib'55. Within the cylindrical passage 54and extending partially within the rib 55 is a hollow cylinder 59 ofresilient bonding material such as rubber. The hollow of the cylinder 59together with the rib 55 defines a cylindrical space in which weposition one end of apin 56. The pin 56 has a relatively small end 57 inthe cylindrical space of the cylinder 59 and a relatively large end58positioned in the bore 27b ofthe sleeve 25. The two ends 57 and 58 ofthe pin 56 meet in a filleted portion, the surface of which conforms toa degree with the inner surface of the rib 55. The portion 57 has adiameterslightly less than the diameter of'the circular opening formedby the rib 55, and the portion 58 adjacent to the other end has adiameter several thousandths of an-inch less than the smaller diameterof the bore 275, said portions 57 and 58 meeting each other in saidfilleted surface. The portion 57 extends into the passage 54 of plug 52through the opening described by the annularrib' 55 so that the annularrib 55 is adjacent to the filleted surface connecting portions 57 and58. The pin 56 is resiliently bonded to the housing by means of theresilient hollow cylinder 59. The plug 52 isscrewed into thebore 27a ofhousing 20 so that that portion 58 of pin 56 extends through the bore27b of sleeve 25. The pin 56thus has 'its free end adjacent to theplunger 41. The top of'ear 46 'of driving washer 45 is in contactwiththe portion 58 of pin 56 when the plunger 41 is in the uppermostposition. Thus it is seen that the pin 56 restricts the upward movementof the plunger 41 sothe plunger may not move upward beyonda=predetermined point. Aftera nail has been driven the spring 50cooperates with the sleeve 25 to drive the plunger 41 upward. When theear 46 of drive washer 45 reaches the pin 56, the upward movement ofplunger 41 is suddenly stopped, resulting in impact forces beingtransmitted to the pin 56. If the pin 56 were rigidly secured, theplunger 41 would theoretically be stopped in zero distance resulting inimpact forces of magnitude sufiicient to shear the pin 56 and to shearthe car 46 from the'drive member 45. To overcome this shearing effect wehave resiliently mounted the pin 56 so that it may move severalthousandths of an inch in bringing the plunger 41to 'a stop. Thisreduces the magnitude of the impact forces to a point where they are nolonger sufiicient to shear the pin 56.

I also provide in my nailing machine, nail feeding means generallydesignated as for continually and positively urging the nailslongitudinally forward through the nail guiding passage 68 of the nailcarrying means 60 into cooperating position with the nail driving means40. The nail feeding means 90 for .urging the nails forward is carriedin part within the body 21 of housing 20 and in part within the nailguiding passage of the nail carrying means 60, and comprises a floatingU-shaped bracket 91 pivotally connected at its open'end tohousing 20 bymeans of a pin 92. The U-shaped bracket 91 rotatably carries a springroller 93 adjacent to its closed end. The roller 93 is mounted on anaxle 97 extending through the legs of the bracket 91 and into the sideof the base 21 of the housing 20. If desired, the axle 97 may beshortened so that it extends through the legs of the bracket 91 and notinto the base 21. Other means of securing the axle end of'b'racket 91 tothe base 21 or of restraining its movement in one direction may beprovided if desired, or the axle end of 91 may be left absolutely freein the base 21. Passing over the roller 93 is a nail follower spring 94having one end attached to the pin 92 and having the other end attachedto a channel shaped nail follower 95 as at 96. The nail follower isslidably positioned in the nail guiding passage 68 of the nail carryingmeans 60 and is in contact engagement with the rearmost or last nail inthe passage 68. The nail feeding means 90 for urging the nails forwardis arranged so that when the housing 20 is closed, the spring 94 exertsa continual positive force keeping the follower 95 in contact engagementwith the said last nail so that it positively urges the nails intocooperating position with the nail driving means 40.

As is evident from the foregoing description, we provide an arrangementwhereby the nail carrying means 60 may be removed easily and quicklyfrom the housing 20 by releasing the latch spring 80 and removing one orboth of the snap rings 67 and the pin 66. This allows one nail carryingmeans to be substituted for another nail carrying means with littleeffort inasmuch as we make the nail carrying means interchangeable. Withthis in mind, we have provided an arrangement whereby the nail carryingmeans will cooperate with the housing 20 to determine the angle at whichthe nails will be driven into the work surface so that one nail carryingmeans, such as 60 (shown in Fig. l), which cooperates with the housing20 to drive the nails at an angle of approximately 45 with the worksurface, may be quickly and easily replaced by another nail carryingmeans such as 160. Such other nail carrying means 160 is shown in Fig.12 and carries, if desired, the same type of nails or, if desired, adifferent type of nails. The nail carrying means 160 cooperates with thehousing 20 to drive nails at another angle, such as 90 with the worksurface. The angle at which the nail carrying means cooperates to drivethe nails is determined entirely by the particular nail carrying meansused and of course may be any predetermined angle from to 90 with thework surface depending upon the construction of the particular nailcarrying means, which construction in this respect will now bedescribed.

Referring now again to Fig. 1, it is seen that the nail carrying means60 is cast integrally with a support portion 81 projecting from itslower side in a position adjacent to the end at which the nails areejected. The support 81 has a Work surface engaging face 82, which ispreferably covered with a floor mat 83 to prevent scratching the worksurface. As seen in Fig. 1, the work surface engaging face 82 makes anangle of approximately 45 with the plane of action of blade 47. Thuswhen the face 82, or the floor mat 83, if such is used, is in face toface engagement with the work surface, the nails are ejected from thenailing machine and driven into the work surface at an angle ofapproximately 45 therewith. In the particular embodiment shown, the leg75 of plate 73 has an angular laterally extending groove 84 cut in itsbottom face having one face parallel to and one face perpendicular tothe work engaging face 82 of support 81. The groove 84 cooperates withthe beading 200 of the board being nailed to keep the nailing machine inthe proper position relative to the Work surface.

The operation of our nailing machine has already been described relativeto the various independent operations of the subassemblies. The generaloperation will now be described with particular reference to Fig. 1.

To load the nails into the machine, the latch spring 80 is disengagedfrom the projection 31 and the nail carrying means 60 is swung in an arcaway from the housing 20, exposing the nail guiding passage 68 andcarrying the stack of nails 300. The nail follower 95 is therebyslidably moved automatically to the end of the nail guiding passage 68covered by the nail stop plate 70. While the follower 95 is so held, astack of nails 300 is dropped into the nail guiding passage 68 so thatthe heads of the nails are in contact engagement with the lip 69 wherebythe nails are slidably carried by the lip 69 as best shown in Fig. 3.The nail carrying means 60 is then swung in an arc toward the housing 20until the latch spring 78 reengages the projection 31 locking the nailcarrying means 60 to the housing 20. The follower 95 is thus moved tothe position shown in Fig. l causing the spring 94 to pull the follower95 into driving engagement with the last nail of stack 300. Before thelatch spring reengages the projection 31, the pins 30 engage the holes79 properly aligning the nail carrying means 60 with the housing 20.After the latch spring 80 has reengaged the projection 31, the machineis ready for use. To drive a nail, the face 82 of the support 86 or thefloor mat 83, if such is used, is placed in face to face contact withthe work surface, in the desired position upon said surface, relativethereto, and the head 42 of plunger 41 is struck a solid blow with ahammer or mallet. This causes the plunger 41 to move downward againstthe force of spring 50, carrying the drive washer 45 with it. The drivewasher 45 in turn, by means of car 46, engages the blade 47, drivingsaid blade downward into driving engagement with the first nail of stack300. Said first nail (as may be clearly understood) has before thistime, by action of the forward urging means 90, been positioned in thedriving throat 76, in cooperating position with regard to the blade 47.The blade 47 thereby drives the nail out of the machine into the worksurface. Since the blade 47 is no thicker than the thinnest nail, itengages only the first nail of stack 300, said nail being stripped fromthe adjacent nail of stack 300 by the stripper plate 77.

The plunger 41 is immediately thereafter returned upwardly by means ofthe spring 50 until the ear 46 of drive washer 45 strikes portion 58 ofretainer pin 56. The force with which the drive washer 45- strikes theretainer pin 56 causes the portion 58 of said pin to move slightlyupward and portion 57 to move slightly downward into the resilientmaterial 59, said pin pivoting upon the filleted surface connecting theportions 57 and 58, of pin 56 whereby the plunger 41 is resilientlybrought to a stop and placed in a position to drive another nail.Portion 57 moving into the resilient material 59 imparts thereto a greatamount of the energy to be absorbed thus reducing the impact force to avalue below that which would shear the pin 56 and/ or the ear 46 of thewasher 45. After the blade 47 clears the now first nail of stack 3%,during the upward movement of plunger 41, the now first nail of stack300 is fed into the driving throat 76 into cooperating position with theblade 47 by the nail feeding means 90, and the machine is ready to driveanother nail.

Where the nail carrying means 60 of my nailing machine is used, inlaying horizontal flooring, the means for urging the nailslongitudinally through the nail carrying means 60 may be omitted sincethe longitudinal axis of the nail guiding passage 68 makes a sufficientangle with a horizontal Work surface (approximately 45) to allow gravityto feed nails properly into cooperating position with the nail drivingmeans 40.

Where this particular arrangement is used, nails may be loaded into themachine as previously described, omitting that part of the procedurerelating to the nail follower. Here the machine may also be loaded byrotating the nail stop plate 71 covering the end of nail guiding passage68, thereby exposing said nail guiding passage, dropping the stack ofnails 300 therein and rotating the nail stop plate back so it againcovers the end of the nail guiding passage.

It is to be understood that the above described embodiments of ourinvention are for the purpose of illustration only and various changesmay be made therein without departing from the spirit and scope of ourinvention.

We claim:

1. In a nailing machine having a housing, a nail driving meanscomprising; a sleevewithin the housing hav ing a bore and formed with alongitudinally extending keyway along theperiphery of the bore of saidsleeve, a cylindrical plunger received in the bore of said sleeve, so asto slidably reciprocate and rotate coaxially therewith, said plungerhaving an enlarged portion adjacent to one end and formed with twoadjacent annular grooves near to but spaced from the other end; a flatblade received in the keyway of said sleeve so as to slidablyreciprocate longitudinally within said keyway and having a projectionnear to but spaced from one end thereof, said projection being receivedin the groove of said plunger nearest the end of said plunger oppositeto the end having the enlarged portion so that said blade is carried bysaid plunger which remains free to rotate within said bore, saidprojection having a depth less than the depth of said groove and havinga width in the axial direction of said plunger substantially less thanthe corresponding dimension of said groove so that said blade is free tofloat for small distances longitudinally relative to said plunger; adrive washer having a rectangular ear and being received in the othergroove of said plunger so that it is carried thereby, said plungerremaining free to rotate co'axially within the bore of said sleeve, saidear being reciprocally and slidably received in the keyway of saidsleeve and engaging said blade during the driving stroke; a compressionspring surrounding the shaft of said plunger and bearing on said sleeveso as to urge said plunger out of the bore of said sleeve; and stopmeans including a stepped cylindrical pin being formed with bodyportions adjacent each end thereof of substantially different diametersconnected by an intermediate filleted annular surface, and a hollowcylinder of resilient material surrounding one end of the pin andsecured within the housing, said pin being pivotally car ried on itsfilleted surface by the housing so that the portion of said pin havingthe larger diameter is movably received within the keyway of said sleeveand is engagedby the ear of said washer during the driving stroke and sothat the portion of said pin having the smaller diameter is resilientlyattached within said housing; whereby said plunger is free to rotaterelative to said sleeve, said blade and said drive washer as saidplunger reciprocates'and whereby said plunger is resiliently restrainedfrom moving out of the bore of said sleeve by said pin engaging the earof said drive washer.

2. In a nailing machine, nail driving means including; a housing havinga bore and formed with a longitudinally extending keyway along theperiphery of said bore; a

cylindrical plunger received in said bore so as to be coaxially andslidably reciprocable and rotatable therein, said plunger having anannular groove adjacent to one end; and a blade slidably received in thekeyway of said housing being longitudinally reciprocable therein andhaving a projection adjacent to one end thereof, said projection beingreceived in the groove of said plunger, having a depth less than thedepth of the groove of said plunger and having a width in the axialdirection of said plunger substantially less than the correspondingdimension of the groove of said plunger; whereby said blade is carriedby said plunger so that said blade is free to float for small distanceslongitudinally relative to said plunger and said plunger is free torotate within said bore.

3. In a nailing machine, nail driving means including; a housing havinga bore and formed with a longitudinally extending keyway along theperiphery of the bore of said housing; a cylindrical plunger received insaid bore so as to be reciprocally and coaxially rotatable and slidabletherein, and formed with two adjacent annular grooves near to but spacedfrom one end; a blade slidably received in the keyway of said housing soas to be longitudinally reciprocable therein, having a projection nearto but spaced from one end thereof, said projection being received inone groove of said plunger, having a depth less than the depth of saidgroove and having a width in the axial direction of said plungersubstantially less than the corresponding dimension of said groove sothat said blade is free to float for small distances longitudinallyrelative to said plunger; and a drive washer having a rectangular earand being received in the other groove of said plunger so that it iscarried thereby, said ear being slidably received in the keyway of saidhousing, so as to be longitudinally reciprocable therein, and engagingsaid blade in driving contact during the driving stroke, whereby saidplunger is free to rotate relative to said blade and said drive washeras said plunger reciprocates.

4. In a nailing machine having a housing, nail driving means comprising;a sleeve in said housing; a plunger received in said sleeve so as to bereci rocably slidable therein for driving nails from the nailingmachine; a. spring bearing on said plunger so as to urge said plungerfrom said sleeve of said housing; and a stepped pin resiliently securedwithin said housing and formed with body portions adjacent each endthereof of substantially diflerent cross section and with anintermediate filleted surface, said pin being pivotally carried on itsfilleted surface by the housing so that the portion of said pin havingthe larger dimension is movably received in said housing, whereby saidpin cooperates with said plunger to resiliently restrain said plungerfrom moving out of said housing.-

5. In a nailing machine having a housing, nail driving means comprisinga cylindrical plunger received in said housing so as to be reciprocablyslidable in a longitudinal direction and reciprocably and slidablyrotatable about its longitudinal axis; a blade received in said housingand rotatably and floatingly carried by said plunger; and a drive washerreciprocally and slidably received in said housing so as to be free toreciprocably slide longitudinally in a channel thereof, said washerbeing carried by said plunger and engaging the blade during the drivingstroke, so that said plunger is free to rotate relative to the housing,blade and drive washer as it reciprocates; a spring in compressionalengagement with said plunger to urge said plunger from said housing; andresilient retaining means for retaining said plunger in said housingagainst the urging force of said spring.

6. In a nailing machine having a housing, nail driving means comprising;a plunger reciprocably received in said housing; a blade reciprocablyreceived in said housing and floatingly carried by said plunger; aspring in compressional engagement with said plunger to urge saidplunger from said housing; and resilient retaining means for retainingsaid plunger in said housing against the urging of said spring.

7. In a nailing machine having a housing, nail driving means comprisinga cylindrical plunger received in said housing so as to be slidably androtatably reciprocable along and about the longitudinal axis of saidplunger; a blade slidably received in said housing so as to belongitudinally reciprocable therein, said blade being floatingly carriedby said plunger; and a drive washer slidably received in said housing soas to be reciprocable longitudinally within a channel of said housing,said washer being carried by said plunger and engaging the blade duringthe driving stroke, so that the plunger is free to rotate relative tothe housing, blade and drive washer as it reciprocates.

References Cited in the file of this patent UNITED STATES PATENTS1,186,458 Von Vass June 6, 1916 2,412,620 Kipp Dec. 17, 1946 2,427,358Kovach Sept. 16, 1947 2,430,321 Anstett Nov. 4, 1947 2,430,322 AnstettNov. 4, 1947 2,525,637 Bell Oct. 10, 1950 2,7142% Jenny Aug. 2, 1955

